External

Ether evaporates very quickly, producing great cold, and consequently the part to which it has been applied becomes white from the contraction of the vessels. The cold is sufficient to cause such marked local anaesthesia that the pain of slight operations, performed upon the part anaesthetized, cannot be felt. To produce this result ether is best applied as a fine spray. If it be rubbed in, or evaporation be prevented, it, like alcohol or chloroform, is an irritant.

Internal

In the mouth and stomach also it acts like chloroform or alcohol. Thus ether causes a burning taste in the mouth, an increase of the saliva, of the gastric secretion and gastric movements, and dilatation of the vessels of the stomach. Consequently it is carminative and aids digestion. Directly after it reaches the stomach it reflexly excites the heart, increasing the force and frequency of the pulse, and causing a rise of blood-pressure; it is one of the best cardiac stimulants we have. In the same way it excites respiration. It is quickly absorbed, and it's stimulating influence on the heart and respiration is continued. It is thus a good instance of a rapidly diffusible stimulant. It is also anti-spasmodic.

Nervous System

Ether is a powerful general anaesthetic. The phenomena and stages of ether anaesthesia are so like those of chloroform anaesthesia that the description already given (see p. 292) will suffice. The following differences, however, should be noticed:

(1) The heart is paralyzed with much greater difficulty by ether than by chloroform.

(2) The same is true of the vaso-motor centre.

(3) And also of the respiratory centre.

(4) Ether is much more irritant to the respiratory mucous membrane, and hence is more liable to increase bronchitis in those already suffering from it.

(5) Ether is much more likely to irritate the kidneys, and those suffering from the various forms of acute or chronic renal disease, or even from renal insufficiency, should be subjected to ether anaesthesia only when it is administered with the greatest caution.

(6) With ether the stage of stimulation is more protracted, therefore there is more struggling.

(7) For the same reason the anaesthetic stage is not reached so soon.

(8) The reduction of temperature is greater with ether.

(9) Ether must be given nearly pure, about 30 per cent. of air to 70 of ethereal vapor; hence it is more difficult to administer.

(10) The smell of ether is more disagreeable, and patients dislike it more.

(11) Ether is eliminated more slowly, and hence the odor lingers about the patient some time.

(12) Ether being very inflammable cannot be used in the close neighborhood of a naked light.

Ether, on account of its greater safety, is more generally used as an anaesthetic in the United States.